'Walhertz' shows a biosemiotic mixture of cultural practices, to which a speculative future contract between the whale society and the human species has led. On the human side, a form of language has developed that is based on the format of the wave packet (soliton) from the original communication of the whales and interweaves this with relics and causal connections of the digital age. People communicate through so-called 'crafts', which - similar to the wave packet of whales - find an equivalent (data density) as a data volume that embodies the potential for discussion and cooperation in the question of how much time can be produced in cooperation. The encryption of this temporary zone works in a similar way to a cryptographic key exchange, in which both or more "trades" become a key pair with the same amount of data (with regard to the individual intention) and thus create the basis for a secure interaction in the midst of the constant public.